Cleansing bars

ABSTRACT

A cleansing bar composition comprising a soap; and a wax having a melting point of about 50° C. to about 75° C., sunflower oil, and myristyl myristate. In one embodiment, the wax is beeswax. The combination of the wax, the sunflower oil, and myristyl myristate allows for the deposition of a hydrophobic material to skin when in use.

BACKGROUND OF THE INVENTION

Various bar aesthetics have been used in marketed products such asstriated, marbled, mottled, and variegated cleansing bars. Bars having astriped or marbled appearance are present in the marketplace such as,for example, IRISH SPRING® bar soap from Colgate-Palmolive Co., COAST®Soap from Procter and Gamble, SKIN SO SOFT® by Avon, DOVE NUTRIUM® fromUnilever and other specialty products including “Lavendel” from Kappus,a German product imported into the United States, and Apothary StoneWashed Refining Soap by Yardley London.

Although variety of soap bars are available in the marketplace, deliveryof benefit agents to the skin has proven difficult in the conventionalbars owing to hydrophobic benefit agent interacting with hydrophobicportions of the surfactant portions of the soap chip. Besides, thoseconventional soap bars that are not produced using co-extrusiontechnology typically use color solutions to get the desired visualeffect and are done so for visual aesthetic purposes only. Consequently,there is a need for formulating cleansing soap bars that achieve similarvisual aesthetic effects while providing multiple benefits such as soapmildness, enhanced deposition of hydrophobic actives to skin, leavingskin feeling smooth, and providing a massaging tool while showering.

BRIEF SUMMARY OF THE INVENTION

The invention is based in part on the finding that a combination ofhydrophobic ingredients comprising wax, sunflower oil, and myristylmyristate in a cleansing bar can provide enhanced deposition ofhydrophobic benefit agents to the skin.

In a first exemplary embodiment the invention is a cleansing barcomposition comprising:

-   a) a soap; and-   b) a wax having a melting point of about 50° C. to about 75° C.,    sunflower oil, and myristyl myristate.

In a second exemplary embodiment, the invention includes a method ofpreparing cleansing bar containing wax blend including:

-   a) heating a wax having a melting point of about 50° C. to about    75° C. until melting and creating a wax melt solution;-   b) introducing sunflower oil, myristyl myristate, and optionally at    least one material chosen from propylene glycol and a hydrophobic    benefit agent into the wax melt solution while heating;-   c) stirring to obtain a homogenous solution;-   d) cooling the solution;-   e) introducing the homogenous solution into a soap component during    extrusion; and-   f) extruding to form a cleansing bar.

In one embodiment, the wax is beeswax.

DETAILED DESCRIPTION OF THE INVENTION

Unless otherwise specified, all percentages and amounts expressed hereinand elsewhere in the specification should be understood to refer topercentages by weight. Also, the term “about,” when used in reference toa range of values, should be understood to refer to either value in therange, or to both values in the range. As used throughout, ranges areused as shorthand for describing each and every value that is within therange. Any value within the range can be selected as the terminus of therange.

As used herein, the term “cleansing bar” shall include soap bars forcleansing and personal hygienic use comprising a cleansing soapmaterial.

As used herein, the term “beeswax” shall include the white or yellow tograyish-brown wax secreted by the honeybee for constructing honeycombs,commercial wax obtained by processing and purifying the crude wax of thehoneybee, and synthetic beeswax. Examples of beeswax that can be usedinclude, but are not limited to, beeswaxes available from Strahl &Pitsch, such as S&P 422, 424, or 426 or synthetic version S&P 772.

The present invention relates to cleansing bars containing a hydrophilicsoap chip component and a blend of hydrophobic ingredients including twoor more of beeswax, sunflower oil, and myristyl myristate and optionallyincluding other benefit agents that can provide multiple benefits suchas for example, providing visual aesthetics, smoothness, soap mildness,and enhanced deposition of hydrophobic actives to the skin

In one exemplary embodiment the invention is cleansing bar compositionincluding:

-   a) a hydrophilic soap component; and-   b) a wax having a melting point of about 50° C. to about 75° C.,    sunflower oil, and myristyl myristate.

Soap Component

The cleansing bar of the present invention includes a soap component. Incertain embodiments the soap component is a hydrophilic soap chip (e.g.,“a base component”). Reference is made to U.S. Pat. No. 6,383,999 (Coyleet al.) and U.S. Pat. No. 6,248,703 (Finucane et al.) each of whichdisclose soap components of a cleansing soap bar. The term “soap” or“soap chip” is used herein in its popular sense, i.e., the alkali metalor alkanol ammonium salts of aliphatic alkane or alkene monocarboxylicacids. Sodium, potassium, mono-, di- and tri-ethanol ammonium cations,or combinations thereof, are suitable for purposes of this invention. Ingeneral, sodium soaps are used in the compositions of this invention,but from about 1% to about 25% of the soap may be ammonium, potassium,magnesium, calcium or a mixture of these soaps.

The soap chips useful herein for the purpose of this invention alsoinclude but are not limited to the well known alkali metal salts ofaliphatic (alkanoic or alkenoic) acids having about as 8 to 22 carbonatoms alkyl, preferably 10 to 20 carbon atoms alkyl chain. These may bedescribed as alkali metal carboxylates of acrylic hydrocarbons havingabout 12 to about 22 carbon atoms. Any other surfactant can also bepresent in the soap chip which include but are not limited to sulfate,sulfonate alpha olefin sulfonates, isethionates such as SCI, taurates,sulfosuccinate, phosphates, glycinates, amphoteric surfactants such asbetaines, sulfobetaines and the like and nonionic surfactants such asalkanolamide, alkylpolyglycosides and all those surfactants, in general,mentioned in Colgate's U.S. Pat. No. 5,139,781, column 5, line 35 tocolumn 11, line 46.

In one exemplary embodiment the cleansing bar of this invention includesat least about 70% by weight of soap active compounds.

In an alternate exemplary embodiment the hydrophilic soap chip of thecomposition of this invention consists essentially of anionicsurfactant, non-ionic surfactants, amphoteric surfactants, cationicsurfactants and mixtures thereof.

Blend of Hydrophobic Ingredients

One embodiment further includes a hydrophobic blend of ingredients inthe cleansing bar which delivers multiple benefits. The hydrophobicblend includes wax, sunflower oil, and myristyl myristate that providesa positive effect to the substrate being cleaned, e.g., the skin. Incertain embodiments the hydrophobic blend additionally includes one ormore of a hydrophobic benefit agent, propylene glycol, and chromiumoxide green. The blend of hydrophobic component maybe incorporateduniformly within the soap chip.

In one embodiment, the combination of wax, sunflower oil, and myristylmyristate (hydrophobic blend) is present in the bar in an amount ofabout 1% to about 5% by weight.

In one embodiment, the combination of wax, sunflower oil, and myristylmyristate (hydrophobic blend) includes beeswax in an amount of about 25to about 37% by weight. In another embodiment, the amount is about 28 toabout 34% by weight.

In one embodiment, the combination of wax, sunflower oil, and myristylmyristate (hydrophobic blend) includes sunflower oil in an amount about7% to about 47% by weight of sunflower oil.

In one embodiment, the combination of wax, sunflower oil, and myristylmyristate (hydrophobic blend) includes myristyl myristate in an amountof about 15% to about 24% by weight.

In some embodiments, a hydrophobic benefit agent is further included inthe combination of wax, sunflower oil, and myristyl myristate(hydrophobic blend). When present, the hydrophobic benefit agent can bepresent in an amount of about 0.001 to about 10% by weight. Any desiredhydrophobic benefit agent can be included in the blend. The blend aidsin deposition of the hydrophobic benefit agent to the skin.

In some embodiments, the combination of wax, sunflower oil, and myristylmyristate (hydrophobic blend) additionally include water-miscibleorganic solvents. The water miscible solvent can be one or morepolyhydric alcohols. Exemplary polyhydric alcohols species include, butare not limited to, propylene glycol and/or polyethylene glycol.

In one embodiment, the combination of wax, sunflower oil, and myristylmyristate (hydrophobic blend) includes the following ingredients:beeswax in an amount of about 28% to about 34% by weight; sunflower oilin an amount of about 7% to about 47% by weight; myristyl myristate inan amount of about 15% to about 24% by weight; optionally a hydrophobicbenefit agent; and optionally propylene glycol.

In another embodiment, the combination of wax, sunflower oil, andmyristyl myristate (hydrophobic blend) of wax and sunflower oil are in aratio of about 1:1 to about 1:6.

The myristyl myristate in the combination of wax, sunflower oil, andmyristyl myristate (hydrophobic blend) allows the blend to wash/wear ata similar rate as soap. This allows the bar to remain smooth. Withoutmyristyl myristate in the blend, the blend is hard, and the bar willbecome bumpy after wear.

The combination of wax, sunflower oil, and myristyl myristate(hydrophobic blend) may be used in any type of bar soap, which includessyndets and combars.

Other Ingredients

Optional ingredients can be present in the cleansing bar composition.Non-limiting examples include skin conditioning agents, moisturizingagents, fragrance, dyes and pigments, titanium dioxide, chelating agentssuch as EDTA, sunscreen active ingredients such as butyl methoxybenzoylmethane, polyols such as polyethylene glycols; antiagingcompounds such as alpha hydroxy acids, beta hydroxy acids; antimicrobialmaterials such as triclocarban, triclosan and the like, preservativessuch as hydantoins, imidazolines; vitamins such as A, E, K and C;essential oils and extracts thereof such as rosewood and jojoba,particulate matter such as polyethylene beads, jojoba beads, lufa, oroat flour, and the mixtures of any of the foregoing components.

In one embodiment the cleansing bar includes fragrance in an amount ofabout 0.001% to about 2% by weight of the composition.

In one embodiment the cleansing bar includes titanium dioxide in anamount of about 0.01% to 1% by weight.

In one embodiment the cleansing bar includes one or more pigments, suchas chromium oxide green, in an amount of about 0.001% to about 1% byweight.

Preparation of Cleansing Bars

In one embodiment, the cleansing bar containing a combination of wax,sunflower oil, and myristyl myristate (hydrophobic blend) may beprepared by heating wax until melting and creating a wax melt solution(hydrophobic component); introducing other components includingsunflower oil, myristyl myristate, optionally propylene glycol,optionally octyl methoxycinnamate, and optionally chromium oxide greeninto the wax melt solution while heating; stirring to obtain ahomogenous solution; cooling the solution to 50 to 55° C.; andintroducing the homogenous solution into a soap component (hydrophiliccomponent) during extrusion; and extruding to form a cleansing bar.

In one embodiment, the cleansing bar of this invention is prepared using(co) extrusion equipment (for example combining the two components).Reference is made to U.S. Pat. No. 3,940,220 (D'Arcageli et al.), U.S.Pat. No. 4,096,221 (Fischer et al.); U.S. Pat. No. 7,128,901 (Jonas etal.), U.S. Pat. No. 4,318,878 (Hornig); U.S. Pat. No. 6,878,319(Browne), each of which describe the process of extrusion andco-extrusion to form a soap bar. Typically, the co-extrusion equipmentincludes two separate pieces of extrusion equipment joined together by acommon co-extrusion nozzle that combines the two streams of soap into adistinct striped or striated pattern.

Cleansing Bar Shapes

The bars of this invention produced by the extrusion method may be ofvarying sizes and shapes such as ovoid or rectangular in shape witheither a flat or curved profile as an overall appearance. It is to benoted that in certain embodiments of the invention, the initial surfaceof the bar may be either smooth or initially have some texture formedduring the extrusion and/or pressing of the bar. Additionally, thehydrophobic components of the soap may be modified to produce variouswearing properties and visual effects. During use, the smooth bar willdevelop appropriate ridges and the non-smooth bars will be able to havetheir texture enhanced. Bar compositions that wear unevenly create bumpysurface that massages the skin during washing and cleansing activities.The cleansing bar can wear evenly or unevenly. The cleansing bar can bemarbled or striated. Also, the soap can be extruded through a shapednozzle to form any desired shape, such as a star.

In other embodiments, the bar is one of a single phase bar, a dual phasebar, a striated bar, or a marbled bar. In some embodiments, thestriation or the marbling is due to addition of the wax blend. Inanother embodiment in a dual phase bar, soap is in one phase and theother phase contains the wax blend.

In one embodiment, the cleansing bar can enhance the deposition ofhydrophobic actives to the skin.

EXAMPLES

Exemplary embodiments of the present invention will be illustrated byreference to the following examples, which are included to exemplify,but not to limit the scope of the present invention.

In the examples and elsewhere in the description of the invention,chemical symbols and terminology have their usual and customarymeanings. Temperatures are in degrees Celsius unless otherwiseindicated. The amounts of the components are in weight percents based onthe standard described; if no other standard is described then the totalweight of the composition is to be inferred. Various names of chemicalcomponents include those listed in the CTFA International CosmeticIngredient Dictionary (Cosmetics, Toiletry and Fragrance Association,Inc., 7^(th) ed. 1997).

In the examples below, octyl methoxycinamate is used as a hydrophobicbenefit agent.

Example 1

A cleansing bar composition is prepared including a hydrophiliccomponent including 1) Soap Chip 96.7%; 2) Titanium oxide 0.55%; 3)Fragrance 1.65%; and a 1.1% hydrophobic component including i) beeswax;ii) sunflower oil; iii) chromium oxide green; with a ratio ofbeeswax:sunflower oil of about 1:1. The formulation is detailed underTable 1.

Example 2

A cleansing bar composition is prepared including a hydrophiliccomponent including 1) Soap Chip 96%; 2) Titanium oxide 0.5%; 3)Fragrance 1.5%; and a 2% hydrophobic component including i) beeswax; ii)sunflower oil; iii) chromium oxide green; with a ratio ofbeeswax:sunflower oil of about 15:85. The formulation is detailed underTable 1.

Example 3

A cleansing bar composition is prepared including a hydrophiliccomponent including 1) Soap Chip 96%; 2) Titanium oxide 0.5%; 3)Fragrance 1.5%; and a 2% hydrophobic component including i) beeswax0.5%; ii) sunflower oil 1.0%; iii) myristyl myristate 0.45%, andpropylene glycol 0.05%. The formulation is detailed under Table 1.

Example 4A

A cleansing bar composition is prepared including a hydrophiliccomponent including 1) Soap Chip 96.4%; 2) Titanium oxide 0.5%; 3)Fragrance 1.5%; 4) octyl methoxycinnamate 1.6% and 0% hydrophobic(beeswax blend) component.

Example 4B

A cleansing bar composition is prepared including a hydrophiliccomponent including 1) Soap Chip 94%; 2) Titanium oxide 0.5%; 3)Fragrance 1.5%; octyl methoxycinnamate 0% and a 4% hydrophobic (beeswaxblend) component.

All bars in Examples 4A and 4B are prepared by adding the beeswax blendas part of the soap (non-striated) so that the benefit derived is not aresult of the concentrated form of the beeswax blend found in certainportions of the bar.

TABLE 1 Cleansing Bar Compositions Example 1 Example 2 Example 3 Example4A Example 4B Ingredients wt % wt % wt % wt % wt % Hydrophilic 96.7 9696 96 94 Component (Soap Chip) Titanium Dioxide 0.55 0.5 0.5 0.5 0.5Fragrance 1.65 1.5 1.5 1.5 1.5 Octyl — — — 1.6 — methoxycinnamate (OMC)Hydrophobic 1.1 2 2 — 4 components including OMC (Beeswax Blend) Textureduring Uneven Uneven Even Single Single phase - washing wear; wear;wear, phase - not soap gets soap gets smooth not applicable bumpy;bumpy; bar applicable exfoliating exfoliating

Table 2 illustrates the cleansing bar formulations containing variousbeeswax blends for Example 4B.

TABLE 2 Various Beeswax Blend for Example 4B Sample W X Y Z Beeswax 27.927.9 27.9 33.6 Sunflower Oil 46.5 7.0 15.0 43.07 Myristyl myristate23.26 23 15 2 Propylene Glycol 2.33 2.33 2.33 2.33 Octylmethoxycinnamate — 39.77 39.77 — (OMC)

Soap Mildness Assay

Soap mildness was measured in vitro using the collagen swelling assay.When the collagen film swells as a result of incubation with the soapsolutions, it absorbs water. The order of collagen swelling observed is:control soap>Example 4B with Z blend>syndet (DOVE™ soap bar). Theresults show that the soap mildness is improved with the hydrophobicbeeswax blend incorporated into the soap chip.

Skin Deposition Assay

Deposition of actives was measured in vitro using Vitro Skin (IMStechnologies) as the substrate. The soap bar of examples 4A and 4B weretested. The benefit agent, octylmethoxy cinnamate (OMC) deposited on thesubstrate was extracted using ethanol, dried down and reconstituted inmethanol. The amount of OMC in the extract was measured using HPLC (highperformance liquid chromatography) with methanol:water as the mobilephase. The results of the deposition on Vitro skin using the cleansingcomposition of Examples 4A and 4B (X and Y) are shown in table 3.

TABLE 3 Deposition of Actives Deposition on Vitro Skin Tests (μg/cm²)Example 4A (control) 1.48 Example 4B with beeswax blend Y 1.67 (p ≦0.05) Example 4B with beeswax blend X 1.60 (p ≦ 0.05

The deposition on Vitro skin tests for Examples 4B with HydrophobicBlend X and Y clearly show that cleansing bar with beeswax enhance thedeposition of hydrophobic actives such as OMC into the skin compared tocleansing bar that does not contain the hydrophobic beeswax blend asevident from the greater quantity of actives assayed for Examples withbeeswax blend with active ingredients.

Skin Feel Tests

The cleansing soap bar was tested for smoothness. Eight test panelistswere recruited for this study. Panelists were asked to wash one forearmwith the cleansing soap of Example 4B (with the beeswax blend) and thecontralateral arm with the control soap of Example 4A (soap withoutbeeswax blend). Seven out of eight panelists preferred the arm washedwith the beeswax blend and the reason cited most often was smoothnessevidencing the benefits of beeswax blend soaps to the skin feel afteruse.

1. A cleansing bar composition comprising: a) a soap; and b) a waxhaving a melting point of about 50° C. to about 75° C., sunflower oil,and myristyl myristate.
 2. The composition of claim 1, wherein the waxis beeswax.
 3. The composition of claim 2, wherein the beeswax andsunflower oil are in a ratio of about 1:1 to about 1:6.
 4. Thecomposition of claim 2, wherein the beeswax, sunflower oil, and myristylmyristate are present in combination in an amount of about 1% to about5% by weight of total cleansing bar composition.
 5. The composition ofclaim 2, wherein the beeswax is present in the beeswax, sunflower oil,and myristyl myristate combination in an amount of about 25 to about 37%by weight.
 6. The composition of claim 2, wherein the beeswax is presentin the beeswax, sunflower oil, and myristyl myristate combination in anamount of about 28% to about 34% by weight.
 7. The composition of claim2, wherein the sunflower oil is present in the beeswax, sunflower oil,and myristyl myristate combination in an amount of about 7% to about 47%by weight.
 8. The composition of claim 2, wherein the myristyl myristateis present in the beeswax, sunflower oil, and myristyl myristatecombination in an amount of about 15% to about 24% by weight.
 9. Thecomposition of claim 2 further comprising propylene glycol.
 10. Thecomposition of claim 9, wherein the propylene glycol is present in thebeeswax, sunflower oil, and myristyl myristate combination in an amountof about 2% to about 3% by weight.
 11. The composition of claim 2further comprising a hydrophobic benefit agent.
 12. The composition ofclaim 11, wherein the hydrophobic benefit agent is present in thebeeswax, sunflower oil, and myristyl myristate combination in an amountof about 0.001% to about 10% by weight.
 13. The composition of claim 1further comprising titanium oxide in an amount of about 0.1% to about 1%by weight.
 14. The composition of claim 1 further comprising chromiumoxide green.
 15. The composition of claim 2, wherein a combination ofbeeswax, sunflower oil, and myristyl myristate comprises beeswax in anamount of about 28% to about 34% by weight; sunflower oil in an amountof about 7% to about 47% by weight; myristyl myristate in an amount ofabout 15% to about 24% by weight; propylene glycol in an amount of about2% to about 3% by weight, and optionally a hydrophobic benefit agent.16. The composition of claim 1, wherein the bar is one of a single phasebar, a dual phase bar, a striated bar, or a marbled bar.
 17. A method ofpreparing a cleansing bar comprising: a) heating a wax having a meltingpoint of about 50° C. to about 75° C. until melting and creating a waxmelt solution; b) introducing sunflower oil, myristyl myristate, andoptionally at least one material chosen from propylene glycol and ahydrophobic benefit agent into the wax melt solution while heating; c)stirring to obtain a homogenous solution; d) cooling the solution; e)introducing the homogenous solution into a soap component duringextrusion; and f) extruding to form a cleansing bar.
 18. The method ofclaim 17, wherein the wax is beeswax.